BACKGROUND: The aim of this study was to evaluate factors influencing the 99th percentile for cardiac troponin I (cTnI) when this cutoff value is established on a highly sensitive assay, and to compare the value of this cutoff to that of lower cutoffs in the prognostic assessment of patients with coronary artery disease. METHODS: We used the recently refined Access AccuTnI assay (Beckman-Coulter) to assess the distribution of cTnI results in a community population of elderly individuals [PIVUS (Prospective Study of the Vasculature in Uppsala Seniors) study; n = 1005]. The utility of predefined cTnI cutoffs for risk stratification was then evaluated in 952 patients from the FRISC II (FRagmin and Fast Revascularization during InStability in Coronary artery disease) study at 6 months after these patients had suffered acute coronary syndrome. RESULTS: Selection of assay results from a subcohort of PIVUS participants without cardiovascular disease resulted in a decrease of the 99th percentile from 0.044 microg/L to 0.028 microg/L. Men had higher rates of cTnI elevation with respect to the tested thresholds. Whereas the 99th percentile cutoff was not found to be a useful prognostic indicator for 5-year mortality, both the 90th percentile (hazard ratio 3.1; 95% CI 1.9-5.1) and the 75th percentile (hazard ratio 2.8; 95% CI 1.7-4.7) provided useful prognostic information. Sex-specific cutoffs did not improve risk prediction. CONCLUSIONS: The 99th percentile of cTnI depends highly on the characteristics of the reference population from which it is determined. This dependence on the reference population may affect the appropriateness of clinical conclusions based on this threshold. However, cTnI cutoffs below the 99th percentile seem to provide better prognostic discrimination in stabilized acute coronary syndrome patients and therefore may be preferable for risk stratification.
BACKGROUND: The aim of this study was to evaluate factors influencing the 99th percentile for cardiac troponin I (cTnI) when this cutoff value is established on a highly sensitive assay, and to compare the value of this cutoff to that of lower cutoffs in the prognostic assessment of patients with coronary artery disease. METHODS: We used the recently refined Access AccuTnI assay (Beckman-Coulter) to assess the distribution of cTnI results in a community population of elderly individuals [PIVUS (Prospective Study of the Vasculature in Uppsala Seniors) study; n = 1005]. The utility of predefined cTnI cutoffs for risk stratification was then evaluated in 952 patients from the FRISC II (FRagmin and Fast Revascularization during InStability in Coronary artery disease) study at 6 months after these patients had suffered acute coronary syndrome. RESULTS: Selection of assay results from a subcohort of PIVUS participants without cardiovascular disease resulted in a decrease of the 99th percentile from 0.044 microg/L to 0.028 microg/L. Men had higher rates of cTnI elevation with respect to the tested thresholds. Whereas the 99th percentile cutoff was not found to be a useful prognostic indicator for 5-year mortality, both the 90th percentile (hazard ratio 3.1; 95% CI 1.9-5.1) and the 75th percentile (hazard ratio 2.8; 95% CI 1.7-4.7) provided useful prognostic information. Sex-specific cutoffs did not improve risk prediction. CONCLUSIONS: The 99th percentile of cTnI depends highly on the characteristics of the reference population from which it is determined. This dependence on the reference population may affect the appropriateness of clinical conclusions based on this threshold. However, cTnI cutoffs below the 99th percentile seem to provide better prognostic discrimination in stabilized acute coronary syndromepatients and therefore may be preferable for risk stratification.
Authors: Gabriela Querejeta Roca; Susan Redline; Brian Claggett; Natalie Bello; Christie M Ballantyne; Scott D Solomon; Amil M Shah Journal: Circulation Date: 2015-08-27 Impact factor: 29.690
Authors: Peter A Kavsak; Andrew Worster; John J You; Mark Oremus; Adell Elsharif; Stephen A Hill; P J Devereaux; Andrew R MacRae; Allan S Jaffe Journal: Clin Biochem Date: 2009-12-21 Impact factor: 3.281
Authors: M Mueller; S Celik; M Biener; M Vafaie; K Schwoebel; K C Wollert; J L Januzzi; H A Katus; E Giannitsis Journal: Clin Res Cardiol Date: 2012-05-25 Impact factor: 5.460
Authors: James L Januzzi; Fabian Bamberg; Hang Lee; Quynh A Truong; John H Nichols; Mahir Karakas; Asim A Mohammed; Christopher L Schlett; John T Nagurney; Udo Hoffmann; Wolfgang Koenig Journal: Circulation Date: 2010-03-01 Impact factor: 29.690
Authors: Christoph Sinning; Till Keller; Tanja Zeller; Francisco Ojeda; Michael Schlüter; Renate Schnabel; Edith Lubos; Christoph Bickel; Karl J Lackner; Patrick Diemert; Thomas Munzel; Stefan Blankenberg; Philipp S Wild Journal: Clin Res Cardiol Date: 2013-11-23 Impact factor: 5.460
Authors: Nicholas L Mills; Kuan Ken Lee; David A McAllister; Antonia M D Churchhouse; Margaret MacLeod; Mary Stoddart; Simon Walker; Martin A Denvir; Keith A A Fox; David E Newby Journal: BMJ Date: 2012-03-15